Patent GB-766650-A (GB)
Title: Improvements relating to electrical time division multiplex information transmittingand receiving systems
Inventor: SHAND GEORGE
IPC: H03K17/52
Filed: 1953-12-08
Abstract: 766,650. Digital electric calculating-apparatus. METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Dec. 6, 1954 [Dec. 8, 1953], No. 34162/53. Class 106 (1). [Also in Group XL (b)] A dynamicizer or staticizer for use in digital computing or telemetry comprises a multi-gap discharge tube, the static signals being applied to or derived from the multiple electrodes and the serial signals being derived from or applied to the common electrode of the tube. In a dynamicizer, Fig. 1, each of nine relay contacts RL1/1-RL9/1, corresponding to nine binary signals, applies either earth (0) or a positive potential (1) to a corresponding one of the cathodes K1-K9 of a multi-cathode discharge tube A. As the discharge is stepped round the tube by a driving circuit V1, V2 the anode potential fluctuates according to the different cathode potentials, short pulses occurring as the discharge passes the guide electrodes. The series-mode pulse train produced at the anode is passed through cathode-followers V3, V4 and is clipped by the action of a diode V7 controlled by a triode V6. The cathode K10 of the tube A is connected to the grid of the triode V6 so that when the discharge passes to that cathode, the diode V7 passes a large pulse for synchronization purposes. In the staticizer, Fig. 2, the pulse train is applied to (a) a triode V14 rendered conducting by the short guideelectrode pulses and applying corresponding pulses to the guide electrodes of multi-cathode tubes B and C to advance the discharge therein; (b) to a pair of clipping diodes V8, V9 arranged to apply small positive (1) or negative (0) potentials to the grid of a triode V10a having a common cathode with a triode V10b so as to cause either the triode V10a or the triode V10b to conduct to raise the anode potential of the tube C or the tube B respectively; and (c) to a triode V12 which is rendered conducting by the large synchronization pulse from the dynamicizer thereby to draw the discharges in the tubes B and C on to their cathodes K10. The variations in the anode potentials of the tubes B and C result in raising the potential of that cathode to which the discharge passes in the tube B on receipt of a " O " signal and in raising the potential of the effective C tube cathode on receipt of a " 1 ". Each pair of corresponding cathodes is connected to a binary storage device such as the one shown which comprises a double triode V11a V11b to the grids of which the corresponding cathodes K1 are connected. Thus, the triodes V11a, V11b conduct on receipt of a " 0 " or a " 1 " respectively. The anode-circuits include a bi-stable relay which consequently assumes an appropriate registering state. The several double triodes V11 may be conditioned for conduction only in the middle of each digit period by means of sampling pulses applied to their cathodes. The sampling pulses may be derived from an oscillator controlled by the synchronization signal to drive the tubes B and C. Instead of representing the binary. digits by different potentials, signals of different frequency may be used and in this case a third frequency may be applied to the cathode K10 of the tube A for synchronization purposes, the tubes V6, V7 then being unnecessary. With such an arrangement the staticizer requires only one multi-gap tube, the anode of which is supplied with the input signal over filter circuits replacing the diodes V8, V9, and each cathode of which is connected by two filters for the two signal frequencies respectively to the associated digitregistering circuit. Other than binary signals may be transmitted by applying more than two alternative signals to each multiple electrode or a continuously variable signal, e.g. frequency may be applied to each multiple electrode for the transmission of a corresponding continuous variable. The capacity of either dynamicizer or staticizer may be increased by using tubes with more cathodes or by duplicating the circuits, gates being provided to render the circuits effective sequentially.